A.1 Manuscript Title: "A new cloning strategy for producing high molecular weight brush-forming poly(amino acids)"

A simple and versatile strategy has been developed for producing de novodesigned, high molecular weight poly(amino acids) using recombinant DNA technology. This method is based on the assembly of modules of DNA that encode for blocks of poly(amino acids) into a commercially available expression vector; there is no need for custom-modified vectors, and no need for intermediate cloning vectors. Additionally, because the design of new protein-like biopolymers can be an iterative process, our method enables sequential modification of a poly(amino acid) product. That is, if a poly(amino acid) is produced and it is determined that the molecular weight needs to be increased, the expression vector can be re-opened and additional DNA modules can be inserted. For example, the polymer composition could be sequentially modified by adding to either its aminoor carboxy-terminus without having to re-start the gene assembly process from the beginning. The feasibility and simplicity of this method is shown in the production of a poly(amino acid) that was designed as a model for polymers that form brush layers on alumina surfaces. The success and flexibility of this method indicates that it can be applied for production of de novo-designed polypeptides in general. It is hoped that this method will contribute towards the rapid development of bio-inspired protein-based polymers for a variety of applications.